Insertion Assembly for Minimally Invasive Spinal Surgery

ABSTRACT

An alignment rod aligns first and second vertebra screw insertion assemblies during a spinal surgical procedure. The alignment rod includes a body portion that is adapted to engage and align the first and second vertebra screw insertion assemblies during a spinal surgical procedure. The alignment rod also includes a positioning post extending from the body portion and adapted to be engaged by a positioning tool adapted to position the alignment rod relative to one of the first and second vertebra screw insertion assemblies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part patent application of U.S.patent application Ser. No. 12/484,711, filed Jun. 15, 2009, whichclaimed the benefit of U.S. Provisional Application No. 61/061,568 filedJun. 13, 2008, the disclosure of which is incorporated herein byreference.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was not made with any government support.

BACKGROUND OF THE INVENTION

This invention relates to the field of orthopedic surgery and moreparticularly to the area of spinal surgery. Spinal surgery can involvethe insertion of pedicle screws into adjacent vertebral bodies.Minimally invasive surgery involves the use of small incisions. The useof small incisions provides for reduced muscle damage, decreased bloodloss, less postoperative pain, reduced scarring, shorter inpatienthospital stay, and improved operative results. During minimally invasivesurgery, pedicle screws can be inserted through small incisions usingimaging or navigational guidance. Small incisions in the patient's skincan be made precisely over the desired location, and pedicle screws canbe inserted utilizing extended tube assemblies. Once all of the desiredscrews have been inserted, a longitudinal member, such as for example arod, can be inserted in a percutaneous manner and secured to the pediclescrews with desired retainers.

However, it can be difficult to maneuver the extended screw assembliesin the event that multiple pedicle screws are being inserted.Additionally, lumbar lordosis can produce crowding in the surgical area,which can result in difficulty in aligning the extended tube assemblies.Thus, there is a need for an improved insertion assembly for placementof pedicle screws that overcomes aforementioned drawbacks of previouslydescribed insertion tube assemblies.

SUMMARY OF THE INVENTION

According to this invention, there is provided a telescopic insertionassembly configured to insert a pedicle screw into a vertebral body. Theinsertion assembly includes an attachment fixture having one endconfigured to mate with the pedicle screw and another end having aridged portion. A center tube is provided having one end slidablyattached to the attachment fixture and another end having an internallyridged portion. A telescoping member has one ridged end configured toslidably attach to the center tube and another end having a yoke. Thetelescoping member is configured to extend the yoke to differentdistances from the center tube. An alignment member is configured tohingeably attach to the yoke of the telescoping member. The alignmentmember is configured to rotate from a first position to a secondposition. The second position of the alignment member is above a topsurface of a patient's skin.

According to this invention, there is also provided a telescopicinsertion assembly configured to insert a pedicle screw into a vertebralbody. The telescopic insertion assembly includes an attachment fixturehaving one end configured to mate with the pedicle screw and another endhaving a ridged portion. A center tube has one end slidably attached tothe attachment fixture and another end having an internal portion. Atelescoping member has one end slidably attached to the center tube andanother end having a collar. The collar includes a plurality ofapertures. The telescoping member is configured to extend the collar todifferent distances from the center tube. An alignment tool has aplurality of prongs configured to engage the plurality of apertures inthe collar. The alignment tool maintains the collar of the telescopingmember at a level above a top surface of a patient's skin.

According to this invention, there is also provided a reducing retainerconfigured for retaining a longitudinal member in a head of a pediclescrew. The reducing retainer includes a retainer portion configured toattach to the head of the pedicle screw and retain a longitudinal memberin the head. An extension section is connected to the retainer portion.The extension section has a weakened area. A head portion is connectedto the extension section and has a drive structure. Rotational movementapplied to the drive structure is configured to seat the longitudinalmember in the head of the pedicle screw. Further rotational movement ofthe drive structure is configured to break the weakened area of theextension section. The extension section and the drive structure can beremoved after the weakened area is broken.

According to this invention, there is also provided an assemblyconfigured for centralizing of a longitudinal member within a pluralityof telescopic insertion assemblies. The assembly includes a rod holderhaving a handle and an extension member. The handle has an aperture. Theextension member has an aperture. The aperture of the extension memberis configured for placement over an extension of a longitudinal member.A centralizer has a handle and an elongated member. The elongated memberis configured for insertion through the aperture in the handle of therod holder. The elongated member is further configured to substantiallyencircle the extension member. The centralizer centralizes thelongitudinal member among the plurality of telescopic insertionassemblies.

According to this invention, there is also provided a center tube foruse in a telescopic insertion assembly. The center tube includes a lowerend configured for releasable attachment to a pedicle screw, a middleportion connected to the lower end and an upper end connected to themiddle portion. A pivotable section is pivotably attached to the middleportion and extends into the upper end. The pivotable section isconfigured to pivot from a first closed position to a second openposition. In the second open position, a passage is formed between thepivotable section and the center tube. The passage is configured toprovide access to position a longitudinal member within the telescopicinsertion assembly.

According to this invention, there is also provided an insertionassembly for penetrating vertebral bodies. The insertion assemblyincludes a cannula having an inner passage, an obturator configured forsubstantial housing within the passage of the cannula and a depth stopattached to the cannula. The depth stop is configured as a marker toindicate the insertion depth of the insertion device.

Various aspects of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a vertebrapenetration device in accordance with this invention.

FIG. 2 is a cross-sectional view of a portion of the first embodiment ofthe penetration device illustrated in FIG. 1.

FIG. 3 is a cross-sectional view of a portion of a second embodiment ofthe penetration device illustrated in FIG. 1.

FIG. 4 is a cross-sectional view of a portion of a third embodiment ofthe penetration device illustrated in FIG. 1.

FIG. 5 is an exploded perspective view of a first embodiment of avertebra screw insertion assembly in accordance with this invention.

FIG. 6 is an exploded perspective view of a second embodiment of avertebra screw insertion assembly in accordance with this invention.

FIG. 7 is a perspective view of a plurality of vertebra screw insertionassemblies shown in an initial orientation.

FIG. 8 is a perspective view of the plurality of vertebra screwinsertion assemblies illustrated in FIG. 7 shown in an alignedorientation.

FIG. 9 is a perspective view of the plurality of vertebra screwinsertion assemblies illustrated in FIG. 8 shown in an aligned andlocked orientation.

FIG. 10 is a perspective view of the plurality of vertebra screwinsertion assemblies illustrated in FIG. 9 having an alignment rodinstalled therein.

FIG. 11 is a perspective view in cross section of a portion of one ofthe plurality of the vertebra screw insertion assemblies illustrated inFIG. 10 together with a rod holder for initially positioning thealignment rod relative to the vertebra insertion assemblies.

FIG. 12 is a sectional elevational view taken along line 12-12 of FIG.11.

FIG. 13 is a perspective view similar to FIG. 11 of a portion of one ofthe plurality of the vertebra screw insertion assemblies, the rodholder, and a centralizer for finally positioning the alignment rodrelative to the vertebra screw insertion assemblies.

FIG. 14 is a sectional elevational view taken along line 14-14 of FIG.13.

FIG. 15 is an enlarged perspective view of portions of the portion ofone of the vertebra screw insertion assemblies, the rod holder, and thecentralizer illustrated in FIGS. 13 and 14.

FIG. 16 is a perspective view of the plurality of the vertebra screwinsertion assemblies, with the rod holder and the centralizer removedand with a plurality of retainers therein.

FIG. 17 is a perspective view of a first embodiment of the alignment rodillustrated in FIGS. 10 through 16.

FIG. 18 is a perspective view of a second embodiment of the alignmentrod illustrated in FIGS. 10 through 16.

FIG. 19 is a perspective view of a second embodiment of an intermediatetube shown in a closed position.

FIG. 20 is a perspective view of the intermediate tube illustrated inFIG. 19 shown in an opened position.

FIG. 21 is a perspective view of a third embodiment of an intermediatetube shown in an opened position.

FIG. 22 is an exploded perspective view of a second embodiment of avertebra screw insertion assembly in accordance with this invention.

FIG. 23 is a schematic sectional elevational view of portions of thefirst vertebra screw insertion assembly illustrated in FIG. 5.

FIG. 24 is schematic sectional elevational view similar to FIG. 23 of analternative arrangement of portions of the first vertebra screwinsertion assembly illustrated in FIG. 5.

FIG. 25 is a perspective view of a third embodiment of the alignment rodillustrated in FIGS. 10 through 16.

FIG. 26 is a perspective view of a fourth embodiment of the alignmentrod illustrated in FIGS. 10 through 16.

FIG. 27 is a perspective view of a fifth embodiment of the alignment rodillustrated in FIGS. 10 through 16.

FIG. 28 is an enlarged side elevational view showing a first version ofany one of the embodiments of the alignment rod illustrated in FIGS. 10through 16 or FIGS. 25 through 27.

FIG. 29 is an enlarged side elevational view showing a second version ofany one of the embodiments of the alignment rod illustrated in FIGS. 10through 16 or FIGS. 25 through 27.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, there is illustrated in FIG. 1 a firstembodiment of a vertebra penetration device, indicated generally at 1,in accordance with this invention. The vertebra penetration device 1 isadapted to penetrate a vertebral body for a purpose that will beexplained below. For example, the vertebra penetration device 1 canpenetrate a vertebral body to form a bone tunnel for use in a surgicalprocedure. The illustrated vertebra penetration device 1 is a Jamshidineedle. However, the vertebra penetration device 1 can be embodied asany other structure.

The illustrated vertebra penetration device 1 includes a cannula 2, anobturator 3 that is slidably disposed within the cannula 2, and a handle4. The handle 4 may include a removable portion 4 a, although such isnot required. The removable portion 4 a of the handle 4 may be connectedto the obturator 3 such that removal of the removable portion 4 a causesremoval of the obturator 3 from the cannula 2.

Referring now to FIG. 2, a portion of the vertebra penetration device 1is illustrated in detail. As shown therein, the illustrated cannula 2 isgenerally hollow and cylindrical in shape. However, the cannula 2 canhave any other desired shape or combination of shapes. The obturator 3extends through an interior of the cannula 2 and is supported forsliding movement relative thereto in any conventional manner. The outersurface of the cannula 2 has a depth indicator 5 provided therein. Thedepth indicator 5 can be embodied as any structure that can function asa marker to indicate the insertion depth of the cannula 2 within avertebra during a surgical procedure. During such a surgical procedure,conventional imaging techniques, such as X-rays and the like, can beused to determine the location of the depth indicator 5 relative to thevertebra, thereby clearly indicating how far the cannula 2 has beeninserted in the vertebra. The depth indicator 5 can be positioned at anydesired predetermined distance from an end of the cannula 2 for thispurpose.

In the illustrated embodiment, the depth indicator 5 has a generallyrectangular cross sectional shape, having side walls that extendgenerally perpendicularly outwardly relative to the outer surface of thecannula 2 and an outer surface that extends generally concentricallyrelative to the outer surface of the cannula 2. However, the depthindicator 5 may be formed having any desired cross sectional shape orsize that protrudes outwardly from the outer surface of the cannula 2.In the illustrated embodiment, the depth indicator 5 extendscontinuously about the outer surface of the cannula 2. However, thedepth indicator 5 can be formed as one or more segments that extendabout the outer surface of the cannula 2 in a non-continuous manner. Theillustrated depth indicator 5 may be formed integrally with theremainder of the cannula 2 or may be formed from a separate piece thatis secured thereto.

FIG. 3 illustrates a portion of a second embodiment of a vertebrapenetration device, indicated generally at 1′. This second embodiment ofthe vertebra penetration device 1′ includes a modified cannula 6 thatsupports the obturator 3 for sliding movement therein. The cannula 6 hasfirst and second dimensional portions that define a modified depthindicator 7 therebetween. The first and second dimensional portions ofthe cannula 6 can have any desired shapes or sizes that define the depthindicator 7. Similarly, the depth indicator 7 can have any desired shapeor combination of shapes. The depth indicator 7 functions in the samemanner as described above in connection with the depth indicator 5 toclearly indicate how far the cannula 2 has been inserted in the vertebraduring a surgical procedure.

FIG. 4 illustrates a portion of a third embodiment of a vertebrapenetration device, indicated generally at 1″. This third embodiment ofthe vertebra penetration device 1″ includes a modified cannula 8 thatsupports the obturator 3 for sliding movement therein. The outer surfaceof the cannula 8 has a depth indicator 9 provided therein. In theillustrated embodiment, the depth indicator 9 has a generally triangularcross sectional shape, having side walls that extend inwardly at annon-perpendicular angle relative to the outer surface of the cannula 8.However, the depth indicator 9 may be formed having any desired crosssectional shape or size that extends inwardly from the outer surface ofthe cannula 8. The depth indicator 9 functions in the same manner asdescribed above in connection with the depth indicator 5 to clearlyindicate how far the cannula 2 has been inserted in the vertebra duringa surgical procedure.

Referring now to FIG. 5, there is illustrated a first embodiment of avertebra screw insertion assembly 10 in accordance with this invention.The vertebra screw insertion assembly 10 is adapted to facilitate thesecurement of a pedicle screw 12 in a hole formed in a vertebra during aspinal surgical procedure (the hole being initially formed by thevertebra penetration device 1 described above). As will be explained indetail below, the axial length of the vertebra screw insertion assembly10 is adjustable to facilitate its use with patients of differing sizesand shapes.

The pedicle screw 12 is conventional in the art and is adapted to beinserted into a vertebra (not shown) in any known manner. Theillustrated pedicle screw 12 includes a threaded portion 13 and a headportion 14. The threaded portion 13 is configured for insertion into thevertebra and can have any desired root diameter, thread diameter, pitch,and number of threads. The head portion 14 includes a generally U-shapedyoke 15, a retainer structure 16, a pair of generally V-shaped driveslots 17, and an internally threaded portion 18 (for purposes ofclarity, the threads of the internally threaded portion 18 are notshown). The pedicle screw 12 can be formed from any desired material.

The vertebra screw insertion assembly 10 also includes a lower portionindicated generally at 20. The lower portion 20 is generally hollow andcylindrical in shape, although such is not required. The lower portion20 has an upper end 21 having a plurality of drive structures 22provided therein. In the illustrated embodiment, the drive structures 22are embodied as a plurality of slots extending downwardly from the upperend 21 of the lower portion 20. However, the drive structures 22 may beembodied as any desired structure. The purpose for the drive structures22 will be explained below. In the illustrated embodiment, the outersurface of the upper end 21 of the lower portion 20 is formed having aplurality of axial retaining structures 23. The illustrated axialretaining structures 23 are a series of concentric annular protrusions.However, the axial retaining structures 23 may be embodied as anydesired structure or series of structures. Alternatively, the axialretaining structures 23 may be omitted and a smooth outer surface beprovided if desired.

The lower portion 20 also has an outwardly extending protrusion 24provided therein. In the illustrated embodiment, the outwardly extendingprotrusion 24 is embodied as a hollow cylindrical protrusion. However,the outwardly extending protrusion 24 may be embodied as any desiredstructure. Alternatively, the outwardly extending protrusion 24 may beomitted if desired. The purpose for the outwardly extending protrusion24 will be explained below.

The lower portion 20 further has a lower end 25 having a plurality ofdrive structures 26 provided therein. In the illustrated embodiment, thedrive structures 26 are embodied as a plurality of generally V-shapedextensions extending downwardly from the lower end 25 of the lowerportion 20. However, the drive structures 26 may be embodied as anydesired structure. The purpose for the drive structures 26 will beexplained below. Lastly, the lower portion 20 of the vertebra screwinsertion assembly 10 has a slot 27 extending axially throughout thelength thereof. The purpose for the slot 27 will be explained below.

The vertebra screw insertion assembly 10 also includes an intermediateportion indicated generally at 30. The intermediate portion 30 isgenerally hollow and cylindrical in shape, although such is notrequired. The intermediate portion 30 has an upper end 31 and a lowerend 32. In the illustrated embodiment, the inner surface of the upperend 31 of the intermediate portion 30 is formed having a plurality ofaxial retaining structures 33. The illustrated axial retainingstructures 33 are a series of concentric annular protrusions. However,the axial retaining structures 33 may be embodied as any desiredstructure or series of structures. Alternatively, the axial retainingstructures 33 may be omitted and a smooth inner surface be provided ifdesired.

The intermediate portion 30 also has a slot 34 provided therein. In theillustrated embodiment, the slot 34 is elongated and extends generallyaxially. However, the slot 34 may have any desired shape. Alternatively,the slot 34 may be omitted if desired. The purpose for the slot 34 willbe explained below.

The lower end 32 of the intermediate portion 30 has a retainingstructure 35 provided therein. In the illustrated embodiment, theretaining structure 35 is embodied as a lip that extends inwardly aboutthe lower end 32 of the intermediate portion 30. However, the retainingstructure 35 may be embodied as any desired structure. The purpose forthe retaining structure 35 will be explained below. Lastly, theintermediate portion 30 of the vertebra screw insertion assembly 10 hasa slot 36 extending axially throughout the length thereof. The purposefor the slot 36 will be explained below.

The vertebra screw insertion assembly 10 also includes an upper portionindicated generally at 40. The upper portion 40 is generally hollow andcylindrical in shape, although such is not required. The upper portion40 has an upper end 41 having a plurality of arms 42 provided therein.Each of the arms 42 has an opening 42 a formed therethrough, althoughsuch is not required. The arms 42 may be embodied as any desiredstructure. The purpose for the arms 42 will be explained below. Theupper portion 40 further has a lower end 43. In the illustratedembodiment, the outer surface of the lower end 43 of the upper portion40 is formed having a plurality of axial retaining structures 44. Theillustrated axial retaining structures 44 are a series of concentricannular protrusions. However, the axial retaining structures 44 may beembodied as any desired structure or series of structures.Alternatively, the axial retaining structures 44 may be omitted and asmooth outer surface be provided if desired. Lastly, the upper portion40 of the vertebra screw insertion assembly 10 has a slot 45 extendingaxially throughout the length thereof. The purpose for the slot 45 willbe explained below.

Lastly, the vertebra screw insertion assembly 10 includes an alignmentbracket, indicated generally at 46. The illustrated alignment bracket 46includes a pair of bracket arms 47 that are connected together by antransverse bar 48. Each of the bracket arms 47 has an inwardly extendingprotrusion 49 (only one is illustrated) provided thereon. However, thealignment bracket 46 may have any desired shape. The purpose for thealignment bracket 46 will be explained below.

Referring now to FIG. 6, there is illustrated a second embodiment of avertebra screw insertion assembly 10′ in accordance with this invention.The second embodiment of a vertebra screw insertion assembly 10′ issimilar to the first embodiment 10 described above, and like referencenumbers are used to identify similar structures. As will be explained indetail below, the axial length of the vertebra screw insertion assembly10′ is also adjustable to facilitate its use with patients of differingsizes and shapes.

The vertebra screw insertion assembly 10′ includes a lower portionindicated generally at 20′. The lower portion 20′ is generally hollowand cylindrical in shape, although such is not required. The lowerportion 20′ has an upper end 21′ having a plurality of drive structures22′ provided therein. In the illustrated embodiment, the drivestructures 22′ are embodied as a plurality of slots extending downwardlyfrom the upper end 21′ of the lower portion 20′. However, the drivestructures 22′ may be embodied as any desired structure. The purpose forthe drive structures 22′ will be explained below. In the illustratedembodiment, the outer surface of the upper end 21′ of the lower portion20′ is formed having a plurality of axial retaining structures 23′. Theillustrated axial retaining structures 23′ are a series of concentricannular protrusions. However, the axial retaining structures 23′ may beembodied as any desired structure or series of structures.Alternatively, the axial retaining structures 23′ may be omitted and asmooth outer surface be provided if desired.

The lower portion 20′ also has an outwardly extending protrusion 24′provided therein. In the illustrated embodiment, the outwardly extendingprotrusion 24′ is embodied as a hollow cylindrical protrusion. However,the outwardly extending protrusion 24′ may be embodied as any desiredstructure. Alternatively, the outwardly extending protrusion 24′ may beomitted if desired. The purpose for the outwardly extending protrusion24′ will be explained below.

The lower portion 20′ further has a lower end 25′ having a plurality ofdrive structures 26′ provided therein. In the illustrated embodiment,the drive structures 26′ are embodied as a plurality of generallyV-shaped extensions extending downwardly from the lower end 25′ of thelower portion 20′. However, the drive structures 26′ may be embodied asany desired structure. The purpose for the drive structures 26′ will beexplained below. Lastly, the lower portion 20′ of the vertebra screwinsertion assembly 10′ has a slot 27′ extending axially throughout onlya portion of the length thereof. The purpose for the slot 27′ will beexplained below.

The vertebra screw insertion assembly 10′ also includes an intermediateportion indicated generally at 30′. The intermediate portion 30′ isgenerally hollow and cylindrical in shape, although such is notrequired. The intermediate portion 30′ has an upper end 31′ and a lowerend 32′. In the illustrated embodiment, the inner surface of the upperend 31′ of the intermediate portion 30′ is formed having a plurality ofaxial retaining structures 33′. The illustrated axial retainingstructures 33′ are a series of concentric annular protrusions. However,the axial retaining structures 33′ may be embodied as any desiredstructure or series of structures. Alternatively, the axial retainingstructures 33′ may be omitted and a smooth inner surface be provided ifdesired.

The intermediate portion 30′ also has a slot 34′ provided therein. Inthe illustrated embodiment, the slot 34′ is elongated and extendsgenerally axially. However, the slot 34′ may have any desired shape.Alternatively, the slot 34′ may be omitted if desired. The purpose forthe slot 34′ will be explained below.

The lower end 32′ of the intermediate portion 30′ has a retainingstructure 35′ provided therein. In the illustrated embodiment, theretaining structure 35′ is embodied as a lip that extends inwardly aboutthe lower end 32′ of the intermediate portion 30′. However, theretaining structure 35′ may be embodied as any desired structure. Thepurpose for the retaining structure 35′ will be explained below. Lastly,the intermediate portion 30′ of the vertebra screw insertion assembly10′ has a slot 36′ extending axially throughout only a portion thelength thereof. The purpose for the slot 36′ will be explained below.

The vertebra screw insertion assembly 10′ also includes an upper portionindicated generally at 40′. The upper portion 40′ is generally hollowand cylindrical in shape, although such is not required. The upperportion 40′ has an upper end 41′ having a plurality of arms 42′ providedtherein. Each of the arms 42′ has an opening 42 a′ formed therethrough,although such is not required. The arms 42′ may be embodied as anydesired structure. The purpose for the arms 42′ will be explained below.The upper portion 40′ further has a lower end 43′. In the illustratedembodiment, the outer surface of the lower end 43′ of the upper portion40′ is formed having a plurality of axial retaining structures 44′. Theillustrated axial retaining structures 44′ are a series of concentricannular protrusions. However, the axial retaining structures 44′ may beembodied as any desired structure or series of structures.Alternatively, the axial retaining structures 44′ may be omitted and asmooth outer surface be provided if desired.

Lastly, the vertebra screw insertion assembly 10′ includes an alignmentbracket, indicated generally at 46. The illustrated alignment bracket 46is the same as described above in connection with the vertebra screwinsertion assembly 10. The purpose for the alignment bracket 46 will beexplained below.

FIG. 7 shows the first embodiment of the vertebra screw insertionassembly 10 in an initial orientation. As shown therein, the lowerportion 20 of the vertebra screw insertion assembly 10 is disposedwithin the intermediate portion 30 thereof such that the protrusion 24is received within the slot 34. The retaining structure 16 of thepedicle screw 12 engages the retaining lip 35 provided on theintermediate portion 30 of the vertebra screw insertion assembly 10, andthe generally V-shaped extensions 26 provided on the lower end 25 of thelower portion 20 are received within the generally V-shaped drive slots17 of the pedicle screw 12. Thus, in a manner that is known in the art,rotation of the lower portion 20 of the vertebra screw insertionassembly 10 which can be accomplished by means of a conventional tool(not shown) that engages the drive slots 22 causes rotation of thepedicle screw 12. Accordingly, the pedicle screw 12 can be threaded intoa bone tunnel, such as might be formed by the vertebra penetrationdevice 1 described above. The retaining bracket 46 is pivotablyconnected to the upper end 42 of the upper portion 40 of the vertebrascrew insertion assembly 10. This can be accomplished by inserting theinwardly extending protrusions 49 provided on the bracket arms 47 intothe openings 42 a provided on the arms 42 of the upper end 41 of theupper portion 40.

The axial length of the vertebra screw insertion assembly 10 isadjustable to facilitate its use with patients of differing sizes andshapes. This is done so that a minimum amount of the vertebra screwinsertion assembly 10 will extend outwardly from the patient, therebyproviding a maximum amount of clearance in the surgical field above theskin of the patient. As discussed above, the lower end 43 of the upperportion 40 of the vertebra screw insertion assembly 10 is receivedaxially within the upper end 31 of the intermediate portion 30 thereof.The upper portion 40 of the vertebra screw insertion assembly 10 canthus be axially positioned relative to the intermediate portion 30thereof by moving the upper portion 40 to a desired position relative tothe intermediate portion 30. This can be accomplished manually, by meansof a tool (not shown), or any other means. When so positioned, the upperportion 40 of the vertebra screw insertion assembly 10 is located in adesired axial position relative to the intermediate portion 30 thereofbased upon the size and shape of the patient.

In order to retain the upper portion 40 of the vertebra screw insertionassembly 10 in the desired axial position relative to the intermediateportion 30 thereof, the illustrated plurality of axial retainingstructures 44 provided on the outer surface of the lower end 43 of theupper portion 40 engages the corresponding plurality of axial retainingstructures 33 provided on the inner surface of the upper end 31 of theintermediate portion 30. In this manner, a desired axial length of thevertebra screw insertion assembly 10 can be achieved and retained forfurther use, as described below. As mentioned above, however, the axialretaining structures 33 and 44 may be embodied as any other desiredstructure or series of structures. Alternatively, the axial retainingstructures 33 and 44 may be omitted and smooth surfaces can be providedif desired. All that is necessary is that the axial length of thevertebra screw insertion assembly 10 be adjustable to facilitate its usewith patients of differing sizes and shapes.

FIG. 7 also shows two of the second embodiment of the vertebra screwinsertion assemblies 10′ in an initial orientation. The arrangement ofthe various elements of the second embodiment of the vertebra screwinsertion assemblies 10′ is the same as described above in connectionwith the first embodiment of the vertebra screw insertion assembly 10.In the same manner as described above, and for the same reason, theaxial lengths of the vertebra screw insertion assemblies 10 areadjustable to facilitate their use with patients of differing sizes andshapes.

As shown in FIG. 7, the slot 27 formed through the lower portion 20 ofthe vertebra screw insertion assembly 10, the slot 36 formed through theintermediate portion 30 of the vertebra screw insertion assembly 10, andthe slot 45 formed through the upper portion 40 of the vertebra screwinsertion assembly 10 are all axially aligned with one another toprovide a continuous slot through the vertebra screw insertion assembly10. As also shown in FIG. 7, this continuous slot through the vertebrascrew insertion assembly 10 is oriented facing inwardly toward theadjacent one of the plurality of vertebra screw insertion assemblies10′. The purpose for this continuous slot and the reason for itsorientation in this manner will be described below.

FIG. 8 shows the plurality of vertebra screw insertion assemblies 10 and10′ illustrated in FIG. 7 shown in an aligned orientation. This isaccomplished by pivoting each of the alignment brackets 46 from theunaligned positions illustrated in FIG. 7 into the aligned positionsillustrated in FIG. 8. In such aligned positions, the alignment bracket46 provided on the vertebra screw insertion assembly 10 engages thealignment bracket 46 provided on the adjacent first vertebra screwinsertion assembly 10. Similarly, the alignment bracket 46 provided onthe first vertebra screw insertion assembly 10′ engages the alignmentbracket 46 provided on the adjacent second vertebra screw insertionassembly 10′. Any number of such vertebra screw insertion assemblies 10and 10′ may be aligned in this manner. In the illustrated embodiment,the alignment brackets 46 engage each other in a nested manner, althoughsuch is not required.

FIG. 9 is a perspective view of the plurality of vertebra screwinsertion assemblies illustrated in FIG. 8 shown in an aligned andlocked orientation. To accomplish this, a locking bracket 50 is engagedwith some or all of the alignment brackets 46 provided on the first andsecond vertebra screw insertion assemblies 10 and 10′. The lockingbracket 50 is optional and may be embodied as any desired structure thatis capable of engaging some or all of the alignment brackets 46 and forpositively maintaining them in desired positions relative to oneanother. Preferably, the locking bracket 50 has at least one opening 51formed therethrough (two are shown in the illustrated embodiment) for apurpose that will be explained below. When the locking bracket 50 isinstalled as shown in FIG. 9, the outer ends of the first and secondvertebra screw insertion assemblies 10 and 10′ are generally locked inalignment with one another.

Next, as shown in FIG. 10, an alignment rod 55 is installed in the firstand second vertebra screw insertion assemblies 10 and 10′. Theillustrated alignment rod 55 includes a body portion 56 having apositioning post 57 extending therefrom. The structure of the alignmentrod 55 will be explained in greater detail below. The alignment rod 55can be installed in the first and second vertebra screw insertionassemblies 10 and 10′ along a path defined by the dotted line A in FIG.10. As mentioned above, the slot 27 formed through the lower portion 20of the vertebra screw insertion assembly 10, the slot 36 formed throughthe intermediate portion 30 of the vertebra screw insertion assembly 10,and the slot 45 formed through the upper portion 40 of the firstvertebra screw insertion assembly 10 are all axially aligned with oneanother to provide a continuous slot through the first vertebra screwinsertion assembly 10. The path defined by the dotted line A in FIG. 10extends through this continuous slot. During insertion, portions of thealignment rod 55 pass through portions of the interior of the firstvertebra screw insertion assembly 10. The continuous slot thus providessufficient clearance for the alignment rod 55 to be installed in thefirst and second vertebra screw insertion assemblies 10 and 10′. When soinstalled, the body portion 56 of the alignment rod 55 is generallyreceived within the generally U-shaped yokes 15 of the pedicle screws12, and the positioning post 57 is generally received within theinterior of the first vertebra screw insertion assembly 10.

After being installed, it is desirable to precisely position thealignment rod 55 relative to the first vertebra screw insertion assembly10. This can be accomplished by means of a first positioning tool,indicated generally at 60 in FIG. 11. As shown therein, the firstpositioning tool 60 includes a handle 61 having a hollow interior 61 aand an elongated shaft 62 that extends from the handle 61. A generallyC-shaped slot 63 is formed through the handle 61 adjacent to the shaft62. The lower end of the shaft 62 has a counterbore 64 formed therein.The first positioning tool 60 can be installed by inserting the shaft 62downwardly through the first vertebra screw insertion assembly 10 suchthat the positioning post 57 of the alignment rod 55 is received withinthe counterbore 64. As best shown in FIG. 12, the positioning post 57 ofthe alignment rod 55 is preferably received snugly within thecounterbore 64 of the first positioning tool 60 such that the alignmentrod 55 and the first positioning tool 60 are precisely positionedrelative to one another. Also, the positioning post 57 of the alignmentrod 55 and the counterbore 64 of the first positioning tool 60 areformed having non-circular cross sectional shapes for a purpose thatwill be explained below.

After the first positioning tool 60 has been installed, a secondpositioning tool, indicated generally at 65 in FIG. 13, is alsoinstalled. As shown therein, the second positioning tool 65 includes ahandle 66 having an elongated generally C-shaped shaft 67 that extendstherefrom. The generally C-shaped shaft 67 is sized and shaped so as toextend through the generally C-shaped slot 63 formed through the handle61 and about the shaft 62 of the first positioning tool 60. As bestshown in FIGS. 14 and 15, the generally C-shaped shaft 67 of the secondpositioning tool 65 is preferably received snugly between outer surfaceof the shaft 62 of the first positioning tool 60 and the inner surfaceof the lower member 20 of the first vertebra screw insertion assembly 10such that the body portion 56 of the alignment rod 55 and the firstvertebra screw insertion assembly 10 are precisely positioned relativeto one another. Consequently, the alignment rod 55 is preciselypositioned relative to the first and second vertebra screw insertionassemblies 10 and 10′.

After being precisely positioned relative to the first and secondvertebra screw insertion assemblies 10 and 10′, the body portion 56 ofthe alignment rod 55 can be secured to each of the second vertebra screwinsertion assemblies 10′. As shown in FIG. 16, this can be done by meansof fasteners 70 that are threaded or otherwise secured to the generallyU-shaped yokes 15 of the pedicle screws 12. The fasteners 70 areconventional in the art and are inserted through each of the secondvertebra screw insertion assemblies 10′ into engagement with thegenerally U-shaped yokes 15 of the pedicle screws 12. When securedthereto, the fasteners 70 precisely position the pedicle screws 12relative to the body portion 56 of the alignment rod 55. As a result,the vertebrae to which each of the pedicle screws 12 are attached arepositioned in accordance with the shape of the body portion 56 of thealignment rod 55.

Next, the second positioning tool 65 is removed from the first vertebrascrew insertion assembly 10 by withdrawing it from the first positioningtool 60. Then, the first positioning tool 60 is removed from the firstvertebra screw insertion assembly 10. The first positioning tool 60 canbe used to remove the positioning post 57 from the alignment rod 55 byrotating the first positioning tool 60 before it is removed from thefirst vertebra screw insertion assembly 10. As mentioned above, thepositioning post 57 of the alignment rod 55 and the counterbore 64 ofthe first positioning tool 60 are formed having non-circular crosssectional shapes. By rotating the first positioning tool 60 before it isremoved from the first vertebra screw insertion assembly 10, thepositioning post 57 can be snapped apart from the alignment rod 55,thereby facilitating its removal when the first positioning tool 60 isremoved from the first vertebra screw insertion assembly 10. Thereafter,another fastener 70 can be threaded or otherwise secured to thegenerally U-shaped yoke 15 of the pedicle screw 12 to secure the firstvertebra screw insertion assembly 10 into engagement with the generallyU-shaped yoke 15 of the associated pedicle screw 12.

FIG. 17 illustrates the structure of the alignment rod 55 in detail. Inthis embodiment, the positioning post 57 and the body portion 56 of thealignment rod 55 are formed integrally from a single piece of material.As shown therein, a recessed area 58 may be provided between thepositioning post 57 and the body portion 56 of the alignment rod 55 tofacilitate the removal of the positioning post 57 from the body portion56 as described above. Alternatively, as shown in FIG. 18, a modifiedpositioning post 57′ and a modified body portion 56′ of an alignment rod55 may be formed from separate pieces of material that are releasablyconnected together. For example, as shown therein, the modifiedpositioning post 57′ and the modified body portion 56′ can havecooperating threaded portions 58′ and 59′ or other structures providedthereon that releasably connect them together.

In the embodiments illustrated in FIGS. 17 and 18, the positioning posts57 and 57′ extend approximately at right angles from the respective bodyportions 56 and 56′. However, the positioning posts 57 and 57′ mayalternatively extend at any desired angle from the respective bodyportions 56 and 56′. For example, FIG. 25 shows the positioning postextending in a generally coaxial direction from an end of the bodyportion. FIG. 26 shows a first modified version of the positioning postextending at an upward angle from the end of the body portion 56, suchas for use as a lordotic rod for a lumbar spine surgical procedure. FIG.27 shows a second modified version of the positioning post extending atan downward angle from the end of the body portion 56, such as for useas a kyphotic rod for a thoracic spine surgical procedure. Additionally,the body portions 56 and 56′ can be formed having either a circularcross sectional shape (as shown in FIG. 28) or a non-circular crosssectional shape (as shown in FIG. 29). As shown in FIG. 29, a flatsurface may be provided on either (or both) sides of the screw-insection of the body portions 56 and 56′ of the alignment rod for theattachment of flanges from the rod holder to provide additionalstability.

As discussed above, the intermediate portion 30 of the first vertebrascrew insertion assembly 10 has a slot 36 extending axially throughoutthe length thereof to provide clearance for the alignment rod 55 to beinstalled in the first and second vertebra screw insertion assemblies 10and 10′. In lieu of such slot 36, however, the intermediate portion 30of the first vertebra screw insertion assembly 10 with a movablesection. In a first modified embodiment of the intermediate portion,indicated generally at 80 in FIGS. 19 and 20, the slot 36 has beenreplaced by a section 81 that is movable relative to the intermediateportion 80 about an axis that is generally transverse to the axialorientation thereof. In a second modified embodiment of the intermediateportion, indicated generally at 82 in FIG. 21, the slot 36 has beenreplaced by a section 83 that is movable relative to the intermediateportion 80 about an axis that is generally parallel to the axialorientation thereof. In both embodiments, the movable sections 81 and 83are sized and shaped to provide clearance for the alignment rod 55 to beinstalled in the first and second vertebra screw insertion assemblies 10and 10′. In both instances, the movable sections 81 and 83 may bemovably supported on the associated intermediate portions 80 and 82 byany desired hinge or other mechanism. Also, in both instances, themovable sections 81 and 83 may be positively maintained in engagementwith the remainders of the intermediate portions 80 and 82 by a retainercap 84 or any other desired structure.

FIG. 22 illustrates a portion of a second embodiment of a vertebra screwinsertion assembly, indicated generally at 100, in accordance with thisinvention. In this modified embodiment, the upper portions 40 and 40′have been replaced with modified upper portions 140 and 140′. The outersurfaces of lower ends 143 and 143′ of the upper portions 140 and 140′are respectively formed having pluralities of axial retaining structures144 and 144′, similar in structure and operation to the plurality ofaxial retaining structures 44 and 44′ described above. Likewise, theupper portion 140 also has a slot 145 that is similar in structure andoperation to the slot 45 described above. In this embodiment, however,the upper portions 140 and 140′ additionally have one or more apertures146 and 146′ respectively formed therethrough. One or more alignmentdevices 147 can extend through these apertures 146 and 146′ to align thevertebra screw insertion assemblies with one another, similar to thealignment brackets 46 discussed above. In use, the upper portions 140and 140′ are axially positioned at desired locations relative to theassociated intermediate portions 30 and 30′ in the same manner and forthe same purpose as described above. If desired, a positioning tool 150can be used to facilitate the axial positioning of the upper portions140 and 140′ at desired locations relative to the associatedintermediate portions 30 and 30′.

FIG. 23 is schematic sectional elevational view of portions of the firstvertebra screw insertion assembly 10 illustrated in FIG. 5. As showntherein, the upper end 21 of the lower portion 20 is received axiallywithin the lower end 32 of the intermediate portion 30, and the lowerend 43 of the upper portion 40 is received axially within the upper end31 of the intermediate portion 30. Alternatively, in a modifiedembodiment shown in FIG. 24, an upper end 221 of a lower portion 220 canbe received axially about a lower end 232 of an intermediate portion230, and a lower end 243 of an upper portion 240 can be received axiallywithin an upper end 231 of the intermediate portion 230.

The above detailed description of the present invention is given forexplanatory purposes. It will be apparent to those skilled in the artthat numerous changes and modifications other than those cited can bemade without departing from the scope of the invention. Accordingly, thewhole of the foregoing description is to be construed in an illustrativeand not a limitative sense, the scope of the invention being defined bythe appended claims.

What is claimed is:
 1. An alignment rod for aligning first and secondvertebra screw insertion assemblies during a spinal surgical procedurecomprising: a body portion that is adapted to engage and align first andsecond vertebra screw insertion assemblies during a spinal surgicalprocedure; and a positioning post extending from the body portion andadapted to be engaged by a positioning tool adapted to position thealignment rod relative to one of the first and second vertebra screwinsertion assemblies.
 2. The alignment rod defined in claim 1 whereinthe positioning post is formed integrally with the body portion.
 3. Thealignment rod defined in claim 2 wherein a recessed area is providedbetween the positioning post and the body portion to facilitate theremoval of the positioning post from the body portion.
 4. The alignmentrod defined in claim 1 wherein the positioning post is formed separatelyfrom the body portion.
 5. The alignment rod defined in claim 4 whereinthe positioning post and the body portion have cooperating structuresprovided thereon that releasably connect them together.
 6. The alignmentrod defined in claim 5 wherein the positioning post and the body portionhave cooperating threaded portions provided thereon that releasablyconnect them together.
 7. The alignment rod defined in claim 1 whereinthe positioning post extends approximately at a right angle from thebody portion.
 8. The alignment rod defined in claim 1 wherein thepositioning post extends in a generally coaxial direction from an end ofthe body portion.
 9. The alignment rod defined in claim 1 wherein thepositioning post extends at an angle from the end of the body portion.10. The alignment rod defined in claim 1 wherein a flat surface isprovided on either or both sides of the body portion.
 11. An assemblycomprising: first and second vertebra screw insertion assemblies; and analignment rod for aligning the first and second vertebra screw insertionassemblies, the alignment rod including: a body portion that is adaptedto engage and align first and second vertebra screw insertion assembliesduring a spinal surgical procedure; and a positioning post extendingfrom the body portion and adapted to be engaged by a positioning tooladapted to position the alignment rod relative to one of the first andsecond vertebra screw insertion assemblies.
 12. The assembly defined inclaim 11 wherein the positioning post is formed integrally with the bodyportion.
 13. The assembly defined in claim 12 wherein a recessed area isprovided between the positioning post and the body portion to facilitatethe removal of the positioning post from the body portion.
 14. Theassembly defined in claim 11 wherein the positioning post is formedseparately from the body portion.
 15. The assembly defined in claim 14wherein the positioning post and the body portion have cooperatingstructures provided thereon that releasably connect them together. 16.The assembly defined in claim 15 wherein the positioning post and thebody portion have cooperating threaded portions provided thereon thatreleasably connect them together.
 17. The assembly defined in claim 11wherein the positioning post extends approximately at a right angle fromthe body portion.
 18. The assembly defined in claim 11 wherein thepositioning post extends in a generally coaxial direction from an end ofthe body portion.
 19. The assembly defined in claim 11 wherein thepositioning post extends at an angle from the end of the body portion.20. The assembly defined in claim 11 wherein a flat surface is providedon either or both sides of the body portion.